IEEE Std 572:2019 pdf free download – IEEE Standard for Qualification ofClass 1E Connection Assemblies forNuclear Power Generating Stationsand Other Nuclear Facilities
4. Background
lt is required that Class lE connection assemblies meet or exceed the specified performance requirementsthroughout their installed life. This is accomplished through a quality assurance program that includes, butis not limited to design, qualification, production quality control, installation, maintenance, periodic testing.and surveillance. The qualification portion of the program is discussed in this standard. The other steps inthe quality assurance program require strict control to ensure that manufactured connection assemblies areconsistent over time and are suitably applied, installed, maintained, and,where required, periodically tested.Maintenance of the qualification of connection assemblies may require action by the end user,such asreplacement of glands or seals following disconnection in service. No specific condition monitoring activitiesfor connection assemblies have been identified.
Testing of each connection assembly size and configuration is not required if qualification families areestablished by analysis based on the same generic design，use of the same production facilities， andproduction of the same thermal,electrical and mechanical stresses.Other IEEE standards，includingIEC/IEEE 60780-323-2016,IEEE Std 382-2006 and IEEE Std 317-2013, provide guidance.
Qualification of connection assemblies may be required for mating to existing connection assemblies orconnection assemblies provided by others. In these cases, the connection assembly shall be qualified with theactual mating connection assembly to be installed in service.Intermatability to other connectors shall neitherbe assumed nor based on manufacturer’s certifications.
lt is the primary role of qualification to ensure that Class lE connection assemblies can perform as specified andthat no failure mechanism exists that could lead to common cause failures under postulated service conditions.
lt is the degradation with time (aging), followed by exposure to the environmental extremes of temperature,pressure, humidity, radiation, vibration,chemical spray, or submergence resulting from design basis events(DBE), extreme natural events, and severe accident conditions (SAC), or a combination of these,whichpresents a potential for causing common cause failures ofClass 1E connection assemblies.For these reasons, itis necessary to establish a qualified life and qualified condition for connection assemblies required to function during andor following a DBE, extreme natural event, and/or SAC.The qualified condition is the state ofdegradation for which successful performance during a subsequent design basis event was demonstrated.Thisshall be accomplished using the qualification methods described in 5.l through 5.4, including type testing,operating experience, analysis as a supplement to type testing and operating experience,ongoing qualification,condition-based qualification in conjunction with type testing, or any combination thereof.
NOTE—At the end of the qualified life, the equipment is capable of performing the safety function(s) required for thepostulated design-basis and post-design basis events (IECIEEE 60780-323-2016).A qualified life is not required forequipment located in a mild environment that has no significant aging mechanisms.
Connection assemblies located in a mild environment area where the environment does not exceed thepostulated normal and abnormal conditions during a DBE(except seismic) may not require pre-agingprior to seismic testing to establish a qualified life or qualified condition. This is appropriate where datahas demonstrated that the connection assembly can perform its Class lE function and has no significantaging mechanisms. If data shows that the connection assembly can perform its Class lE function, then theequipment’s qualified life and qualified condition may be equated to its design life.If evaluations of designsand applications of particular connection assemblies so indicate, pre-aging prior to seismic testing is notrequired by this standard.However, if the connector is disconnected for maintenance, periodic testing, orsurveillance, then the number of connect-disconnect operations shall be simulated prior to seismic testing.The documentation required to qualify the connection assembly may be less than that required for connectionassemblies described in the preceding paragraph.
For all qualification, the end result shall be documentation that demonstrates the connection assembly ‘sadequacy to perform its Class lE function(s).The documentation shall be in an auditable form that allowsverification by competent personnel, other than the qualifier, and shall contain the connection assembly ‘squalification specification, documents that demonstrate compliance with the qualification specification andinstallation requirements,periodic inspection and maintenance requirements,summaries,information formaintaining qualification, and conclusions.